/*
 * Copyright (c) 2016, 2021, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

package java.awt.desktop;

import java.awt.Desktop;
import java.awt.GraphicsEnvironment;
import java.awt.HeadlessException;
import java.io.File;
import java.io.Serial;
import java.util.ArrayList;
import java.util.List;

/**
 * Auxiliary event containing a list of files.
 *
 * @since 9
 * @sealedGraph
 */
public sealed class FilesEvent extends AppEvent
    permits OpenFilesEvent,
            PrintFilesEvent {

    /**
     * Use serialVersionUID from JDK 9 for interoperability.
     */
    @Serial
    private static final long serialVersionUID = 5271763715462312871L;

    /**
     * The list of files.
     */
    @SuppressWarnings("serial") // Not statically typed as Serializable
    final List<File> files;

    /**
     * Constructs a {@code FilesEvent}.
     *
     * @param  files the list of files
     * @throws HeadlessException if {@link GraphicsEnvironment#isHeadless()}
     *         returns {@code true}
     * @throws UnsupportedOperationException if Desktop API is not supported on
     *         the current platform
     * @see Desktop#isDesktopSupported()
     * @see java.awt.GraphicsEnvironment#isHeadless
     */
    FilesEvent(final List<File> files) {
        this.files = files;
    }

    /**
     * Gets the list of files.
     *
     * @return the list of files
     */
    public List<File> getFiles() {
        return files == null
                ? null
                : new ArrayList<>(files);
    }
}
